Simulation of the thermal Characteristics and laminar flow field around the mechanical seal' rings

In this paper, the Numerical investigation of conjugate heat transfer associated with laminar flow within the chamber of a mechanical seal is presented. For this purpose, the N-S equations and the energy equation within the flow of seal chamber, rotating ring and the stationary ring are solved simultaneously. So, a special kind of mechanical seal that belongs to Ebara pump company (pump's name: FSHA 40*50) is employed. Design of 3-D geometry and net production is done in ANSYS (a commercial mechanical software) software. Moreover ANSYS-CFX software is used for simultaneous solving of the Mentioned equations. A series of simulation results are presented for predicting the performance of a seal assuming that the flow in the seal chamber remains laminar and the viscosity with temperature is considered fixed. The computational model takes into account the temperature distribution within the rotating and stationary rings. Expressions are developed for predicting the convective heat transfer coefficient on the outer surfaces of the seal rings exposed to the process fluid in the seal chamber. Furthermore, the thermal parameters and processes fluid characteristics, around the seal is surveyed. For example, the Temperature distributions and local and average convective heat transfer coefficient and Nusselt number are calculated and shown for the shaft speed 1500 rpm. The results show that the interfacial heat generation is mainly convected to the seal chamber flow near the contact face. The maximum heat flux also occurs on the rotating ring surface near the contact face. Finally, Comparison between CFD prediction and the correlation results shows that this CFD simulation is reliable.

Keywords:

Mechanical seal , CFD_CFX , flow field , heat transfer analysis , heat transfer coefficient , heat flux